Curtain clamping structure for gasholders



April 15,1969 J. H. WIGGINS CURTAIN CLAMPING STRUCTURE FOR GASHOLDERS Sheet of 2 Filed March 15. 1965 Han man!!! INVENTOR. JOHN H. W/GG/NS A T TORNE Y5 April 15, 1969 J. H. WIGGINS CURTAIN CLAMPING STRUCTURE FOR GASHOLDERS Sheet 2 01*2 Filed March 15, 1965 J w G F M m Z a m m W1 w J I 1 uw 6 9 n III I! m w F W k a a w a V I N VE N TOR. JOHN H. W/GG/NS A 7' TORNEVS United States Patent 0 3,438,758 CURTAIN CLAMPING STRUCTURE FOR GASHOLDERS John H. Wiggins, P.O. Box 418, Menlo Park, Calif. 94025 Filed Mar. 15, 1965, Ser. No. 439,756 Int. Cl. F17b 1/24 US. Cl. 48-174 6 Claims ABSTRACT OF THE DISCLOSURE A gasholder having a side wall and a piston disposed concentrically thereof and a sealing curtain attached to the side wall and to the piston by sealing structure, the sealing structure including a sealing bar held in position by a series of clamping keys each having a recess at one end to engage the sealing bar and having a foot on the other end to engage the adjacent wall to hold the clamping key in spaced relation from the sealing curtain, and nut and bolt fasteners for mounting the clamping keys on the associated wall, the end of the clamping key engaging the sealing bar being shaped to have a recess to receive a sealing bar and a nose with an outer curved configuration projecting beyond the sealing bar properly to control the bending of the curtain during the folding thereof over the clamping key.

The present invention relates to low pressure gasholders of the curtain seal type and is particularly concerned with a construction for clamping a sealing curtain to an outer backstop structure such as the tank side wall.

It is an object of the invention to provide a seal connection for a curtain to the tank side wall which is of simple and economical construction and comprises a single compact key part which performs functions which currently require more than one part.

A further object of the invention is to provide a seal connection for a curtain to the tank side wall wherein the clamping key locates the sealing bar in a special recessed area, being shaped inside advantageously to position the sealing bar and to distribute the forces applied for clamping the curtain and being shaped outside to guide the curtain through a smooth curved form to prevent local high bending stresses in the curtain as the gasholder is filled and emptied.

Still another object of the invention is to provide a clamping key for a seal connection for a curtain in which the securing means for clamping the key in place is provided in a recessed location where it will not use any clearance room and will not distort the curtain when it is pressed over the key under pressure of the gases in the gas container.

Still another object of the invention is to provide curtain clamping and shape control means for narrowing the required working gap about 3 inches in radial dimension which will provide an equal net working gap for the reciprocating mechanical parts during the rise and fall of the piston thereby greatly improving the operational conditions for the seal since now it is required to compress /3 to A less.

Still a further object of the invention is to provide a curtain seal connection to the tank side wall of minimum radial dimension whereby either the size of the tank can be reduced without reducing its capacity or wherein the capacity of the tank can be increased, by reducing the volume of dead or unusable space in the gas containing portion of the gasholder.

Other objects of the invention will be apparent from the following description of certain preferred embodiments of the invention in the attached specification, taken with reference to the accompanying drawings, in which:

FIGURE 1 is a fragmentary elevational view of the portion of the interior of the gas container showing a number of the seal connections or clamping keys in place inside of the tank side wall and also on the piston Within the tank side wall.

FIG. 2 is an enlarged vertical sectional view of the structure shown in FIG. 1, the plane of the view being indicated by the line 2-2 in FIG. 1.

FIG. 3 is an enlarged fragmentary View of one of the clamp connections or clamping keys shown in FIG. 1.

FIG. 4 is a sectional view of the clamping key shown in FIG. 3 as indicated by the line 4-4 in FIG. 3.

FIG. 5 is a fragmentary plan view of a modified form of clamping key, the view being partially in section and with certain parts broken away to illustrate the details of construtcion.

FIG. 6 is a plane view of another form of clamping key of the type illustrated in FIG. 5 with a sealing bar shown in fragmentary fashion.

FIG. 7 is a view similar to FIG. 6, but with the clampin g nut and bolt omitted.

FIG. 8 is a front elevational view of the clamping key shown in FIG. 6, the view being indicated by the line 8-8 in FIG. 6.

FIG. 9 is a sectional view through the clamping key, the sealing bar, the curtain and the tank side wall, the plane of the view being indicated generally by the section line 99 in FIG. 5.

Referring first to FIGS. 1, 2, 3 and 4 there is shown a gas container of the general type disclosed in the patent to Wiggins et al., No. 2,723,908, and as disclosed in my co-pending application Ser. No. 432,582, filed Feb. 15, 1965, for Dry Seal Pressure Type Gas Holder, and such tanks commonly include a vertical cylindrical side wall 10 with respect to which an inner piston structure 11 is mounted for relative up and down movement as the amount of gas within the gasholder is. changed, and a flexible sealing curtain 12 is provided between the tank wall 10 and the piston structure 11 to allow rising and falling movements of the piston structure 11 while maintaining a tight seal. In this structure, it is important that the sealing curtain 12 have a suitable working space or gap G between the tank wall and the inner curtain backstop surface 13 of the piston structure 11 so that the backstop surface 13 is free to clear the clamping keys 17 on the tank side wall 10 as the piston structure 11 rises and falls. For example, as shown in dotted lines in FIG. 2, the curtain 12 has been reversed from. its full line position and extends upwardly and is guided through a smooth curved form by the convex portion 21b of the nose 21 of the clamp key 17 as the curtain is pressed against the clamp key 17 and the wall 10 by the pressure of the gas within the tank. It is important that the seal connection to the tanke side wall 10 be effective in producing the required gas-tight seal and that the connection be of a minimum thickness or radial dimension so as to enable the gap G to be as narrow as possible for the least amount of compression of the sealing curtain 12 as it passes back and forth over the loop 12a of FIG. 2 and to enable the tank to be of minimum size and have the least dead space for a given capacity while retaining the desired working space or clearance for the curtain 12 and the reciprocating mechanical parts.

In accordance with the instant invention there is pro vided a clamping or sealing bar 16 and a plurality of clamping key-s 17 which serve to secure the upper edge of the curtain 12 as shown in FIG. 2 and FIG. 4 in gas tight relation with respect to the wall 10. It will be understood that a series of clamping bars 16 are provided in end-to-end fashion around the inner circumferential tank side wall 10 to accomplish the seal between the curtain 12 and the wall 10 and the securing of the curtain 12 to the wall 10. Referring more particularly to FIGS. 3 and 4 the clamping key 17 may be formed as an extrusion and has at one end a foot 18, which is connected by a body 19 to the rounded recessed nose 21. The rounded nose 21 has its recessed surface of special shape to fit tightly and complementarily with respect to the sealing bar 16. In this case the recessed surface 21a of the nose 21 is formed concave so as to fit the rounded contour of the cooperating surface of the sealing bar 16. The engagement of the nose 21 over the bar 16 and the engagement of the foot 18 with the tank side wall 10 beyond the end of the curtain 12 spaces the body 19 of the key 17 from the tank side wall 10 to provide :a curtain receiving recess. The outer surface of the nose 21 is also rounded as shown at 2111 on a proper radius to provide a projecting portion which provides a smooth curtain engaging contour and surface 2112 that is spaced from the outer surface 19a of the body 19 to provide a mounting recess for a nut 22 which is threaded on a suitable bolt 23 secured in the tank side wall 10. The threaded portion of the bolt 23 is short and is of insufficient length to project beyond the face of the nut 22 which therefore provides a protective stop surface for the curtain 12 which is flush with the curve 211).

It will be noted that the aperture 190 which provides clearance for the threaded portion of the bolt 23 is spaced closer to the area of application of pressure to the bar 16 than the area of engagement of the foot 18 with the tank side wall 10, so that a major portion of the clamping force exerted by the bolt 23 and the cooperating nut 22 is applied to the bar 16 with reference to the amount of pressure applied by the foot 18 to the wall 10. Also the recessed character of the clamping key 17 provided by the length of the foot 18 and the spacing apart from the wall 10 by virtue of the bar 16 provides for an undistorted positioning of the end of the curtain 12.

A number of these clamping keys 17 are provided for each of the sealing bars 16 and similarly a corresponding number of clam-ping keys 26 of a modified form (later described) are utilized in clamping the other end of the curtain 12 to a circular angle 27 on the piston structure 11 and mounted above the bottom wall 28 of the piston structure 11.

Referring to FIGS. 5 through 9 there is shown a second form of clamping key 26 which may be provided as a steel casting, for example. The key 26 is provided with a body 31 having an aperture 32 for clearance for the securing stud or bolt, and a pair of feet 33 at one end and a recessed nose 37 at the other. A rib 34 projects from the body 31 of the clamping key 26 in the opposite direction to the first and has a rounded contour to form, with the clamping nose 37, a recess to receive a nut 38 for a clamp ing bolt 39. In this case the recess in the nose 37 is formed of rectangular contour to cooperate with a rectangular clamping or seal bar 41, which engages the seal curtain 12:

Referring to FIG. 9 in particular, it will be seen that the rounded contour 37a of the clamping nose 37 and the rounded contour 34a of the rib 34 provide for accurate and smooth control of the curtain 12 when it is folded over and pressed against these surfaces by the gas pressure within the tank, while at the same time providing a protecting well or recess to receive the nut 38.

The clamp kay or seal connection of the instant invention is advantageous in the fact that it is essentially a single member, and it locates the clamp bar for the seal in a specially recessed area at one end of the clamp key where the major portion of the force of the clamping bolt and nut is applied. The clamp key safely controls the shape of the seal or curtain to prevent undesired sharp bending of the seal. It provides an unrestricted housing for the portion of the sealing curtain between the foot of the clamp key and the sealing bar and also provides a recess for the nut which secures it in place so that no ext-r-a gap space is required. The clamp key of the instant invention provides a minimum of space radially, and in the usual construction it would require only about /1 to 1 inch radius of space, whereas the former clamping and shape control means has required as much as 3% inches of a total working gap of 8 to 14 inches between the side wall and the piston. As the seal passes from the outer to the inner backstop the narrower gap obtained materially reduces the operating compression on the seal.

While I have shown and described certain preferred embodiments of the invention it will be apparent that the invention is capable of variation from the forms shown so that the scope thereof shall be limited only by the scope of the claims appended hereto.

What I claim is:

1. In a tank for containing gas, said tank having an upright wall surface, a member movable with respect to said upright wall surface and having a second wall surface, and a flexible sealing curtain attached respectively to said wall surfaces; the combination of a sealing bar for securing said curtain adjacent to at least one edge thereof to one of said wall surfaces, and a series of clamping keys for clamping said sealing bar in place to hold said curtain in sealed relation to said one wall surface structure, each of said clamping keys having a recess at one end thereof formed complementary to and engaging over said sealing bar, said clamping key having a foot at the other end to engage said one wall surface and to hold the body of said clamping key in spaced relation from said curtain, said clamping key having an aperture therein, and a fastening bolt secured to said one wall surface and extending through said aperture and having a nut positioned thereon to mount said clamping key with said foot disposed beyond the adjacent edge of said curtain and with said recessed end disposed toward the center of said curtain and to apply clamping pressure to said clamping key, said recessed end having a nose with an outer surface of curved configuration projecting from said one wall surface slightly beyond the associated sealing bar properly to control the bending of said curtain in folding over said clamping key when said curtain is moved by relative movement between said wall surfaces.

2. In a tank as set forth in claim 1, in which the body of said clamping key is provided with a surface that bears against said nut, said last-mentioned surface being offset with respect to said outer surface of curved configuration toward said one wall surface when installed to form a recess for said nut.

3. In a tank for containing gas, said tank having an upright wall surface, a member movable with respect to said upright wall surface and having a second wall surface spaced with respect to said upright wall surface, and a flexible sealing curtain attached respectively to said wall surfaces; the combination of a sealing bar for securing said curtain adjacent to at least one edge thereof to one of said wall surfaces, and a series of clamping keys for clamping said sealing bar in place to hold said curtain in sealed relation to said one wall surface, each of said clamping keys having a recess at one end thereof formed complementary to and engaging over said sealing bar, said clamping key having a foot at the other end to engage said one wall surface and to hold the body of said clamping key in spaced relation from said curtain, and securing means for clamping said clamping key to said one wall surface with said foot disposed beyond the adjacent edge of said curtain and with said recessed end disposed toward the center of said curtain, said securing means being connected to said clamping key at a location spaced closer to said recessed end than to said foot to distribute a greater proportion of clamping force applied thereto to said sealing bar.

4. In a tank as set forth in claim 3, in which said clamping key is provided with a rib at the other end projecting outwardly from said foot for a distance substantially equal to the projection of said recessed one end from said body to provide a well between said one end and said rib for receiving a securing means in protected position.

5. In a tank as set forth in claim 3, in which said one end is of a protruding rounded shape on the side opposite to said curtain, said rounded shape controlling the shape of said curtain to prevent a sharp bending when said curtain is pressed thereover under gas pressure.

6. A tank as set forth in claim 3, in which each of said clamping keys is provided with rounded curtain engaging surfaces on the side spaced from said one wall to insure smoothness of said curtain when pressed thereover under gas pressure.

References Cited UNITED STATES PATENTS 1 JAMES H. TAYMAN, JR., Primary Examiner.

US. Cl. X.R. 

